TextView 的字数监听

textView.addTextChangedListener(new TextWatcher() {      //对输入窗口的字数监听      @Override      public void beforeTextChanged(CharSequence s, int start, int count,              int after) {      }        @Override      public void onTextChanged(CharSequence s, int start, int before,              int count) {      String content = textView.getText().toString();      send_msg_top.setText(content.length() + "/140" );    }@Overridepublic void afterTextChanged(Editable arg0) {// TODO Auto-generated method stub}    });